Objective: The objective of this investigation was to assess the potential effect of obesity on the effectiveness of hormonal contraceptives (HCs).
Study Design: A meta-analysis was conducted using individual participant data directly from the Phase 3 clinical trials of combination oral contraceptives (COCs) rather than extracting summary data from literature. Trials selected were reviewed by the US Food and Drug Administration (FDA) between 2000 and 2012, conducted in North America, had more than six 28-day cycle equivalents of exposure, and had readily retrievable participant-level data.